The new Capazza dirigible is a decided departure from all preceding constructions, and may mark a new era in the navigation of the air. Its gas envelope is shaped like a lens, or a lentil, and is arranged to sail flatwise with the horizon, thus partaking of the aeroplane as well as the balloon type. No definite facts concerning its achievements have been published. [Illustration: Capazza dirigible from the front. From above it is an exact circle in outline.] Chapter XV. BALLOONS: HOW TO OPERATE. Preliminary inspection--Instruments--Accessories--Ballast--Inflating--Attaching the car--The ascension--Controls--Landing--Some things to be considered--After landing--Precautions. The actual operation of a balloon is always entrusted to an experienced pilot, or “captain” as he is often called, because he is in command, and his authority must be recognized instantly whenever an order is given. Nevertheless, it is often of great importance that every passenger shall understand the details of managing the balloon in case of need; and a well-informed passenger is greatly to be preferred to an ignorant one. It is ordinarily one of the duties of the captain to inspect the balloon thoroughly; to see that there are no holes in the gas-bag, that the valve is in perfect working order, and particularly that the valve rope and the ripping cord are not tangled. He should also gather the instruments and equipment to be carried. The instruments are usually an aneroid barometer, and perhaps a mercury barometer, a barograph (recording barometer), a psychrometer (recording thermometer), a clock, a compass, and an outfit of maps of the country over which it is possible that the balloon may float. Telegraph blanks, railroad time tables, etc., may be found of great service. A camera with a supply of plates will be indispensable almost, and the camera should be provided with a yellow screen for photographing clouds or distant objects. The ballast should be inspected, to be sure that it is of dry sand, free from stones; or if water is used for ballast, it should have the proper admixture of glycerine to prevent freezing. It is essential that the inflating be properly done, and the captain should be competent to direct this process in detail, if necessary. What is called the “circular method” is the simplest, and is entirely satisfactory unless the balloon is being filled with pure hydrogen for a very high ascent, in which case it will doubtless be in the hands of experts. When inflating with coal-gas, the supply is usually taken from a large pipe adapted for the purpose. At a convenient distance from the gas-main the ground is made smooth, and the ground cloths are spread out and pegged down to keep them in place.